Summary

Identity metasystems are finally beginning to mature, based on growing support for "Laws of Identity" (see reference below or [http://www.identityblog.com/?page_id=352]) and frustration with the problems of userid/password authentication.

Users will want OS support for securely selecting identities to use with web services.

To guard against phishing, the identity selection should take place in a protected subsystem (similar to the login screen). The user should get a clear and unmistakable signal that she is indeed talking with this protected subsystem and not something that just looks like one provided by a phisherman.

Rationale

Providing a user interface which makes it clear to the user that they are interacting directly with a layer of the operating system that is more resistant to attack than the browser or other application would increase user confidence and reduce phishing attacks.

There is already a Firefox plugin to do this. But implementing this purely in an application like a browser leaves the user's identity information more vulnerable, and the user more confused about when it is ok to type in their password.

We will also want to enable more flexible and secure authentication methods for many networked activities besides traditional browsing.

Use cases

Scope

This spec is focussed on the client side.

Besides an Identity Selector, other Ubuntu specs are needed for other InfoCard support services. E.g. probably a Card Store to store a user's cards; a log ala the Microsoft "Ledger" that tracks a user's usage of cards at various sites/services; and a Self-Issued Identity Security Token Service (STS) that can be an identity provider for self-issued cards.

Support for the server side (Relying Parties) and for Identity Provider implementations will come through applications such as Apache.

Design

The Identity Selector would probably consist of a protected user interface, and a protocol module to get tokens via interactions with Security Token Services.

Implementation

One promising code base is OSIS - Open Source Identity Selector, which intends to be at least as functional, and fully compatible, with Microsoft's CardSpace (formerly known as InfoCard) identity selector that will be shipped with Windows Vista.